The present invention relates to a method for monitoring reagent delivery in a scanning spectrophotometer and a reagent useful in such a method.
A problem in current reagent delivery systems is that once a reagent has been added to a reaction mixture, it is difficult to determine the actual amount of the reagent present in the reaction mixture. This is a particular problem in blood coagulation assays. In this type of assay, when a blood coagulating reagent such as thromboplastin or thrombin is aspirated into a pipette, air may be drawn into the pipette, so that an insufficient amount of the reagent may be dispensed.
Another problem with assays of the above type is that it may not be possible to easily determine whether there is a plasma sample to be tested present in the reaction cuvette.